Sensex heavyweights Reliance Industries and Tata Consultancy Services contributed to the gains.
The domestic stock markets extended their record-setting spree to Wednesday's session as both benchmarks opened on fresh highs ahead of the Reserve Bank of India's third-bi-monthly monetary policy for fiscal 2019.
After opening at 37,643.87, the Sensex hit an intra-day high of 37,711.87.
The 30-share Sensex surged past 37,700 for the first time ever.
The broader Nifty50 opened at 11,359.80 and hit an intra-day high of 11,390.55, its lifetime high.
At 9:43 am, the SP BSE Sensex traded at 37,635.80, with a gain of 29.22 points or 0.08 per cent while Nifty50 was at 11,372.55 level, up 16.05 points or 0.14 per cent.